Two-axis trajectory control system

ABSTRACT

A trajectory control system includes a first control mechanism having a pair of outputs operably associated with a first pair of control surfaces, the first control mechanism operable to articulate the first pair of control surfaces in unison and a second control mechanism having a pair of outputs operably associated with a second pair of control surfaces, the second control mechanism operable to articulate the second pair of control surfaces in unison. The second control mechanism is nested in the first control mechanism such that the pair of outputs of the first control mechanism is substantially coplanar with the pair of outputs of the second control mechanism.

BACKGROUND

1. Field of the Invention

The present invention relates to systems for controlling the trajectoryof airborne or waterborne vehicles.

2. Description of Related Art

Airborne or waterborne vehicles, such as missiles, rockets, torpedoes,and the like, are often used to deliver a payload to a target locationor to carry a payload over a desired area. For example, vehicles may beused in combat situations to deliver a payload, such as an explosivewarhead or a kinetic energy penetrator, to a target to disable ordestroy the target. Surveillance vehicles may carry a payload designedto sense certain conditions surrounding the vehicle, such as objects onthe ground or weather activity. Such a vehicle typically includes atrajectory control system having a plurality of control surfaces, suchas fins, canards, flares, etc., that are articulated by a system tocontrol the vehicle's direction and attitude.

Some vehicles are large in size and, thus, can accommodate large systemsfor articulating the vehicle's control surfaces. A large articulationsystem, however, may not be desirable, because less volume of thevehicle is available for propellant and payload. A smaller vehicle maysimply not be viable for the purpose intended for the vehicle if thearticulation system occupies a large percentage of the vehicle's volume.For example, a smaller vehicle may not be able to reach a desired targetor may not be capable of carrying sufficient payload if the articulationsystem occupies a large volume percentage of the vehicle. Outerdiameters of some projectile-type vehicles, such as rockets andmissiles, are constrained in size by the type of equipment used tolaunch the vehicle. For example, “shoulder-launched” vehicles orvehicles launched from personnel carriers often are limited in outerdiameter, as well as overall size. Larger, conventional articulationsystems for control surfaces are not well suited for use in suchvehicles.

Other conventional trajectory control systems provide articulationsystems that move each of the control surfaces independently to providecontrol over roll, pitch, and yaw. In some operational environments,vehicle roll is not a concern. In other words, it is not important thatthe roll orientation of the vehicle be maintained during operation ofthe vehicle. Using a trajectory control system that provides rollcontrol when the vehicle roll is not important unduly adds to the cost,complexity, and weight of the vehicle.

Conventional two-axis trajectory control systems that control pitch andyaw of a vehicle are not sufficiently compact to lend their use insmaller vehicles. Moreover, such conventional two-axis trajectorycontrol systems are not configured to withstand the extreme loadsexperienced during high velocity maneuvers, such as those employed bykinetic energy projectiles. Conventional two-axis trajectory controlsystems are typically complex, requiring many different components to bemanufactured and assembled.

It is generally desirable, however, for such vehicles to be lighter inweight, rather than heavier, so that their ranges may be extended whileusing an equivalent amount of propellant. Further, it is generallydesirable for the contents of the vehicle other than the payload, e.g.,the motors, power transmission assemblies, and the like, to be morecompact, so that larger payloads may be used within the body of theprojectile. It is also often desirable to decrease the complexity ofcalculating the required orientation of the control surfaces to attainthe desired vehicle orientation and commanding the actuation apparatusesto orient the control surfaces accordingly.

There are many designs of trajectory control systems well known in theart; however, considerable shortcomings remain.

SUMMARY OF THE INVENTION

There is a need for an improved trajectory control system.

Therefore, it is an object of the present invention to provide animproved trajectory control system.

This and other objects are achieved by providing a trajectory controlsystem that includes a first control mechanism having a pair of outputsoperably associated with a first pair of control surfaces, the firstcontrol mechanism operable to articulate the first pair of controlsurfaces in unison and a second control mechanism having a pair ofoutputs operably associated with a second pair of control surfaces, thesecond control mechanism operable to articulate the second pair ofcontrol surfaces in unison. The second control mechanism is nested inthe first control mechanism such that the pair of outputs of the firstcontrol mechanism is substantially coplanar with the pair of outputs ofthe second control mechanism.

In another aspect, the present invention provides a trajectory controlsystem. The system includes a first control mechanism having outputscoupled with a first pair of control surfaces, the first controlmechanism operable to articulate the first pair of control surfaces inunison and a second control mechanism having outputs coupled with asecond pair of control surfaces, the second control mechanism operableto articulate the second pair of control surfaces in unison. The firstcontrol mechanism includes a motor; an axle coupled with the first pairof control surfaces; and a worm shaft operably associated with the motorand the axle, such that the axle rotates when the motor is activated.The outputs of the first control mechanism are substantially coplanarwith the outputs of the second control mechanism.

In yet another aspect of the present invention, a trajectory controlsystem is provided. The trajectory control system includes a firstcontrol assembly operably associated with a first pair of controlsurfaces for articulating the first pair of control surfaces in unisonand a second control assembly operably associated with a second pair ofcontrol surfaces for articulating the second pair of control surfaces inunison. The second control assembly includes a housing portion; an endcap attached to the housing portion, and a motor rotatably supported bythe housing portion and the end cap. The motor has an output shaft towhich a motor gear is fixedly attached. The second control assemblyfurther includes a worm drive gear engaged with the motor gear, a wormshaft rotatably supported by the housing portion and engaged with theworm drive gear, and a worm shaft end stop fixedly attached to the wormshaft and rotatably supported by the first control assembly. The secondcontrol assembly further includes an axle drive nut engaged with theworm shaft and an axle coupled with the axle drive nut and the secondpair of control surfaces.

The present invention provides significant advantages, including: (1)providing a two-axis trajectory control system that occupies a smallervolume of a vehicle than conventional trajectory control systems; (2)providing a two-axis trajectory control system that is less complex inconstruction than conventional trajectory control systems; and (3)providing a two-axis trajectory control system that can withstand theloadings experienced during high velocity vehicle operation.

Additional objectives, features, and advantages will be apparent in thewritten description which follows.

DESCRIPTION OF THE DRAWINGS

The novel features believed characteristic of the invention are setforth in the appended claims. However, the invention itself, as well as,a preferred mode of use, and further objectives and advantages thereof,will best be understood by reference to the following detaileddescription when read in conjunction with the accompanying drawings,wherein:

FIG. 1 is a partially exploded, perspective view of an illustrativeembodiment of a two-axis control surface actuation system according tothe present invention;

FIG. 2 is a partially exploded, perspective view of the control surfaceactuation system of FIG. 1;

FIG. 3 is an exploded view of an illustrative embodiment of a controlassembly of the control surface actuation system of FIG. 1;

FIG. 4 is a partially exploded, perspective view of an axle and relatedelements of the control surface actuation system of FIG. 1;

FIG. 5 is a partially exploded, perspective view of a vehicleincorporating the control surface actuation system of FIG. 1;

FIG. 6 is a cross-sectional view of a portion of the axle of FIG. 4 takealong line 6-6 of FIG. 4;

FIG. 7 is a perspective view of a control surface member according tothe present invention;

FIG. 8 is a partially exploded, perspective view of a portion of thevehicle of FIG. 5; and

FIG. 9 is a partially exploded, perspective view of the vehicle of FIG.5.

While the invention is susceptible to various modifications andalternative forms, specific embodiments thereof have been shown by wayof example in the drawings and are herein described in detail. It shouldbe understood, however, that the description herein of specificembodiments is not intended to limit the invention to the particularforms disclosed, but on the contrary, the intention is to cover allmodifications, equivalents, and alternatives falling within the spiritand scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Illustrative embodiments of the invention are described below. In theinterest of clarity, not all features of an actual implementation aredescribed in this specification. It will of course be appreciated thatin the development of any such actual embodiment, numerousimplementation-specific decisions must be made to achieve thedeveloper's specific goals, such as compliance with system-related andbusiness-related constraints, which will vary from one implementation toanother. Moreover, it will be appreciated that such a development effortmight be complex and time-consuming but would nevertheless be a routineundertaking for those of ordinary skill in the art having the benefit ofthis disclosure.

In the specification, reference may be made to the spatial relationshipsbetween various components and to the spatial orientation of variousaspects of components as the devices are depicted in the attacheddrawings. However, as will be recognized by those skilled in the artafter a complete reading of the present application, the devices,members, apparatuses, etc. described herein may be positioned in anydesired orientation. Thus, the use of terms such as “above,” “below,”“upper,” “lower,” or other like terms to describe a spatial relationshipbetween various components or to describe the spatial orientation ofaspects of such components should be understood to describe a relativerelationship between the components or a spatial orientation of aspectsof such components, respectively, as the device described herein may beoriented in any desired direction.

The present invention represents a two-axis system for controlling thetrajectory of an airborne or waterborne vehicle. In particular, thepresent system articulates a plurality of control surfaces, such as aplurality of fins, to adjust the pitch and/or yaw of the vehicle. Asused in the present application, the term “control surface” means astructure, such as an airfoil, that is moveable to control or guide anairborne or waterborne vehicle. In a preferred embodiment, the presentsystem includes a housing that encloses a first control mechanism,operably associated with a first pair of control surfaces, and a secondcontrol mechanism, operably associated with a second pair of controlsurfaces. The control mechanisms nest with respect to one another suchthat the output shafts of the control mechanisms are coplanar.Preferably, the control mechanisms are identical in configuration toreduce the cost and complexity of the system. The control mechanisms aredisposed in different portions of a housing. Each of the controlmechanisms and the housing portion corresponding to the controlmechanism forms a control assembly. The control assemblies mate with oneanother to form a control surface actuation system.

FIG. 1 and FIG. 2 provide partially exploded, perspective views of anillustrative embodiment of a two-axis control surface actuation system101 according to the present invention. Control surface actuation system101 comprises a housing 103, a first control mechanism 105, a secondcontrol mechanism 107, and a plurality of locking rings 109. Housing 103comprises a first portion 111 in which first control mechanism 105 isdisposed and a second portion 113 in which second control mechanism 107is disposed. First portion 111 and first control mechanism 105 make up afirst control assembly 115. Second portion 113 and second controlmechanism 107 make up a second control assembly 117. Control lines 119extend between trajectory control mechanisms 105, 107 and, for example,a guidance computer for the vehicle.

Locking rings 109 engage first portion 111 of housing 103 and secondportion 113 of housing 103 to retain first portion 111 to second portion113. As control mechanisms 105, 107 are disposed in portions 111, 113,respectively, locking rings 109 retain first control assembly 115 tosecond control assembly 117. By way of example and illustration, lockingrings 109 are but one means for retaining first portion 111 of housing103 to second portion 113 of housing 103. Moreover, locking rings 109are but one means for retaining first control assembly 115 to secondcontrol assembly 117. Each of first control mechanism 105 and secondcontrol mechanism 107 are configured to mate with and articulate a pairof control surfaces (not shown in FIG. 1 or 2), as will be discussed ingreater detail below. Moreover, first control mechanism 105 and secondcontrol mechanism 107 are configured to mate with one another, as willalso be described in greater detail below.

In the illustrated embodiment, first portion 111 of housing 103 andfirst control mechanism 105 are substantially equivalent in constructionto second portion 113 of housing 103 and second control mechanism 107,respectively. In other words, first portion 111 of housing 103 issubstantially equivalent in construction to second portion 113 ofhousing 103 and first control mechanism 105 is substantially equivalentin construction to second control mechanism 107. Accordingly, firstcontrol assembly 115 is, preferably, substantially equivalent inconstruction to second control assembly 117. It should be noted that theembodiment illustrated in FIGS. 1 and 2 is merely preferred. Otherembodiments are contemplated by the present invention wherein firstcontrol assembly 115 is different in construction from second controlassembly 117. For example, first portion 111 of housing 103 may differin construction from second portion 113 of housing 103, so long as firstportion 111 can be retained to second portion 113. In another example,first control mechanism 105 may differ in construction from secondcontrol mechanism 107, so long as first control mechanism 105 and secondcontrol mechanism 107 mate with one another or the outputs of firstcontrol mechanism 105 and second control mechanism 107 are coplanar. Itshould be noted that first portion 111 of housing 103 (and, thus, firstcontrol mechanism 105) is clocked at about 90 degrees with respect tosecond portion 113 of housing (and, thus second control mechanism 107),as illustrated in FIG. 2.

FIG. 3 provides an exploded view of first portion 111 of housing 103 andfirst control mechanism 105. As the preferred embodiment of the presentinvention contemplates second control assembly 117 to be substantiallyequivalent in construction as first control assembly 115, the followingdescription of first control assembly 115 applies equally to secondcontrol assembly 117. It should be noted that components of secondcontrol assembly 117, when referenced herein, are referred to by thecorresponding element reference number of first control assembly 115,followed by the prime mark. For example, as will be discussed below,first control mechanism 105 comprises an end cover 301. In the preferredembodiment, second control mechanism 107 comprises an end cover 301′having a construction corresponding to end cover 301.

First control mechanism 105, in the illustrated embodiment, comprisesend cover 301, bearings 303 a-303 f, a rotor 305, a stator 307, a motorgear 309, a worm drive gear 311, a worm shaft 313, a worm shaft end stop315, an axle drive nut 317, and an axle 319. Rotor 305 and stator 307make up a motor 321 that, when powered and activated, provides themotive force for actuating first control mechanism 105. Rotor 305 isrotatably supported by end cover 301 via bearing 303 a. Rotor 305 isalso rotatably supported by first portion 111 of housing 103 via bearing303 b. Rotor 305 comprises a rotor shaft 323 fixedly coupled with motorgear 309. Motor gear 309 is engaged with worm drive gear 311, such thatworm drive gear 311 rotates when motor 321 rotates. Worm drive gear 311is fixedly coupled with worm shaft 313, such that worm shaft 313 rotateswhen worm drive gear 311 rotates. Worm shaft 313 is rotatably supportedby first portion 111 of housing 103 via bearing 303 c. Worm shaft endstop 315 is fixedly coupled with worm shaft 313.

Still referring to FIG. 3, worm shaft end stop 315 is rotatablysupported by second portion 113 (not shown in FIG. 3 but shown in FIGS.1 and 2) of housing 103 via a bearing 303 d′ (shown in FIG. 2) of secondcontrol mechanism 107. A worm shaft end stop 315′ (shown in FIG. 2) ofsecond control mechanism 107 is rotatably supported by first portion 111of housing 103 via bearing 303 d. The coupling of worm shaft end stop315 to second portion 113 of housing 103 via bearing 303 d′ incombination with the coupling of worm shaft end stop 315′ to firstportion 111 of housing 103 via bearing 303 d is but one means for matingfirst control assembly 115 to second control assembly 117. Moreover, thecoupling of worm shaft end stop 315 to second portion 113 of housing 103via bearing 303 d′ in combination with the coupling of worm shaft endstop 315′ to first portion 111 of housing 103 via bearing 303 d is butone means for mating first control mechanism 105 to second controlmechanism 107.

Axle drive nut 317 is engaged with worm shaft 313, such that axle drivenut 317 traverses along worm shaft 313 when worm shaft 313 rotates. Axledrive nut 317 is coupled with a clevis 325 of axle 319, such that axle319 rotates about a longitudinal axis 327 of axle as axle drive nut 317traverses along worm shaft 313. It should be noted that axle drive nut317 is coupled with clevis 325 of axle 319 so that axle drive nut 317rotates about an axis 329 that is substantially parallel to axis 327. Inthe present embodiment, as best illustrated in FIG. 4, axle drive nut317 comprises an upwardly extending pin 401 a and a downwardly extendingpin 401 b. Pins 401 a and 401 b each define a groove 403 a and 403 b,respectively, configured to receive one of spring clips 405 a and 405 b,respectively. Bushings 407 a and 407 b each define an opening 409 a and409 b, respectively. Pin 401 a is disposed through opening 409 a ofbushing 407 a and spring clip 405 a is placed in groove 403 a of pin 401a to retain bushing 407 a on axle drive nut 317. Pin 401 b is disposedthrough opening 409 b of bushing 407 b and spring clip 405 b is placedin groove 403 b of pin 401 b to retain bushing 407 b on axle drive nut317. Bushing 407 a is disposed in a recess 411 a of an upper arm 413 aof clevis 325. Bushing 407 b is disposed in a recess 411 b of a lowerarm 413 b of clevis 325. Bushings 407 a and 407 b are retained inrecesses 411 a and 411 b, respectively via the engagement of axle drivenut 317 and worm shaft 313 when first control assembly 115 is mated withsecond control assembly 117.

Note also that axle 319 includes a bend, generally at 419, that isconfigured to receive axle 319′ (shown in FIG. 2). Preferably axle 319′has a configuration corresponding to axle 319, such that axles 319 and319′ nest with respect to one another generally at bend 419 of axle 319and the corresponding bend of axle 319′. Such a configuration conservesthe volume required for control surface actuation system 101.Accordingly, longitudinal axis 327 of axle 319 and longitudinal axis327′ (shown in FIG. 2) of axle 319′ (and, thus, the outputs of controlmechanisms 105 and 107) are substantially coplanar.

Returning now to FIG. 3, axle 319 is rotatably supported by firstportion 111 of housing 103 and second portion 113 (shown in FIGS. 1 and2) of housing 103 via bearings 303 e and 303 f when locking rings 109are engaged with first portion 111 and second portion 113. Accordingly,when power is applied to motor 321 and motor 321 is activated viacontrol lines 119, rotor shaft 323 rotates, which, in turn rotates motorgear 309. Motor gear 309 rotates worm drive gear 311, which, in turn,rotates worm shaft 313. Worm shaft 313 advances axle drive nut 317 alongworm shaft 313, which, in turn, rotates axle 319 about longitudinal axis317.

FIG. 5 depicts one particular embodiment of a trajectory control system501 according to the present invention. In the illustrated embodiment,trajectory control system 501 comprises a plurality of control surfacemembers 503 a-503 d operably associated with control surface actuationsystem 101. Control surface members 503 a-503 d each comprises acorresponding shaft 505 a-505 d extending from a control surface 507a-507 d. Shafts 505 a and 505 b are coupled with axle 319 of firstcontrol mechanism 105, while shafts 505 c and 505 d are coupled withaxle 319′ (shown in FIG. 2) of second control mechanism 107. In theparticular embodiment illustrated in FIG. 5, control surfaces 507 a-507d are fins. The scope of the present invention, however, is not solimited. Rather, control surfaces 507 a-507 d may exhibit other forms,such as flares, canards, or the like. First control mechanism 105 isactuated to articulate control surfaces 507 a, 507 b in unison, viashafts 505 a, 505 b, respectively, and change the yaw (indicated by anarrow 508 a) of a vehicle 509 comprising trajectory control system 501.Second control mechanism 107 is actuated to articulate control surfaces507 c, 507 d in unison, via shafts 505 c, 505 d, to change the pitch(indicated by an arrow 508 b) of vehicle 509. It should be noted that,in a preferred embodiment, longitudinal axis 327 of axle 319 issubstantially coplanar with a longitudinal axis 327′ (shown in FIG. 2)of axle 319′. Accordingly, outputs of axles 319 and 319′ (and, thus, theoutputs of control mechanisms 105 and 107) are coplanar in such apreferred embodiment.

Referring to FIGS. 3, 5, and 6, axle 319 of first control mechanism 105comprises couplings 331 a and 331 b that are adapted to mate withcontrol surface members 503 a and 503 b, respectively. Axle 319′ (shownin FIG. 2) of second control mechanism 107 comprises couplings 331 a′and 331 b′ (also shown in FIG. 2) that are adapted to mate with controlsurface members 503 c and 503 d, respectively. The following descriptionpertains particularly to axle 319 and coupling 331 a thereof. It shouldbe noted, however, that the construction of coupling 331 b correspondsto the construction of coupling 331 a in the preferred embodiment.Moreover, the construction of axle 319′ corresponds to the constructionof axle 319 in the preferred embodiment.

Reference is now made to axle 319 of FIG. 4, the cross-sectional view ofcoupling 331 a of FIG. 6, and control surface member 503 a of FIG. 7.Coupling 331 a defines a groove 601 (shown in FIG. 6) configured toreceive a retainer 701 (shown in FIG. 7) attached to shaft 505 a ofcontrol surface member 503 a. Retainer 701 retains shaft 505 a incoupling 331 a. Shaft 505 a defines a groove 703 that, when aligned witha passageway 415 a defined by coupling 331 a, receives a pin 417 a.Coupling 331 b defines a corresponding passageway 415 b. An interfacebetween pin 417 a, coupling 331 a, and shaft 505 a, provides a baseorientation of control surface member 503 a with respect to firstcontrol assembly 115. It should be noted that, in the preferredembodiment, control surface member 503 b is retained in coupling 331 band is provided with a base orientation with respect to first controlassembly 115 in the same manner as discussed above in relation tocontrol surface member 503 a. Referring to FIG. 3, in the preferredembodiment, control surface member 503 c is retained in coupling 331 a′and control surface member 503 d is retained in coupling 331 b′ in thesame way as described above in relation to control surface member 503 a.Moreover, in the preferred embodiment, control surface members 503 c and503 d are provided with base orientations with respect to second controlassembly 117 in the same way as discussed above concerning controlsurface member 503 a.

Referring again to FIG. 3, first control mechanism 105 further comprisesa position sensor 333 that senses the position of one or more othercomponents of first control mechanism 105 to determine the orientationof control surface members 503 a and 503 b with respect to first controlassembly 115. In various embodiments, position sensor 333 comprises aHall-effect sensor, a photodiode-type sensor, or the like, that sensesteeth of motor gear 309. In one embodiment, position sensor 333 outputsa signal, for each tooth of motor gear 309 sensed, to a controller, suchas the guidance computer, so that the controller can determine theorientation of control surface members 503 a and 503 b with respect tofirst control assembly 115. Note that, in a preferred embodiment, secondcontrol mechanism 107 comprises a corresponding position sensor (notshown) that operates in the same way as position sensor 333. It shouldbe noted, however, that such position sensors are merely examples of ameans for sensing an orientation of a pair of control surfaces (e.g.,control surfaces 507 a, 507 b or control surfaces 507 c, 507 d) or apair of control surface members (e.g., control surface members 503 a,503 b or control surface members 503 c, 503 d) according to the presentinvention. Other constructions of such a means are possible andencompassed within the scope of the present invention.

Referring again to the particular embodiment of FIG. 5, control surfaceactuation system 101 is operably associated with a body 511 of vehicle509 by sliding, as indicated by arrow 519, control surface actuationsystem 101 into a cavity 513 defined by body 511. With control surfaceactuation system 101 disposed in cavity 513, as shown in FIG. 8, pins801 are inserted through pin openings 515 defined by body 511 and intopin openings 121 defined by housing 103. By way of example andillustration, pins 801 are but one means for retaining control surfaceactuation system 101 in body 511 of vehicle 509. Moreover, mechanicalloads experienced during operation of vehicle 509 are efficientlytransmitted from control surface members 503 a-503 d, through controlsurface actuation system 101, to body 511. As illustrated in FIG. 9,control surface members 503 a-503 d are then inserted into couplings 331a-331 d through openings 517 defined by body 511, such that retainers701 are received in grooves 403 defined by couplings 331 a-331 d toretain control surface members 503 a-503 d in couplings 331 a-331 d andpins (e.g., pins 417 a and 417 b) are received in grooves 601 of shafts505 a-505 d to provide base orientations for control surface members 503a-503 d.

The particular embodiments disclosed above are illustrative only, as theinvention may be modified and practiced in different but equivalentmanners apparent to those skilled in the art having the benefit of theteachings herein. Furthermore, no limitations are intended to thedetails of construction or design herein shown, other than as describedin the claims below. It is therefore evident that the particularembodiments disclosed above may be altered or modified and all suchvariations are considered within the scope and spirit of the invention.Accordingly, the protection sought herein is as set forth in the claimsbelow. It is apparent that an invention with significant advantages hasbeen described and illustrated. Although the present invention is shownin a limited number of forms, it is not limited to just these forms, butis amenable to various changes and modifications without departing fromthe spirit thereof.

1. A two-axis trajectory control system, comprising: a first controlmechanism having a pair of outputs operably associated with a first pairof control surfaces, the first control mechanism operable to articulatethe first pair of control surfaces in unison; and a second controlmechanism having a pair of outputs operably associated with a secondpair of control surfaces, the second control mechanism operable toarticulate the second pair of control surfaces in unison; wherein thesecond control mechanism is nested in the first control mechanism suchthat the pair of outputs of the first control mechanism is substantiallycoplanar with the pair of outputs of the second control mechanism. 2.The two-axis trajectory control system, according to claim 1, furthercomprising: a housing comprising a first portion in which the firstcontrol mechanism is disposed and a second portion, mated with the firstportion, in which the second control mechanism is disposed; and meansfor retaining the first portion to the second portion; wherein the firstcontrol mechanism and the second control mechanism are each supported bythe first portion of the housing and the second portion of the housing.3. The two-axis trajectory control system, according to claim 1, furthercomprising: a position sensor operably associated with one of the firstcontrol mechanism and the second control mechanism.
 4. The two-axistrajectory control system, according to claim 1, wherein the firstcontrol mechanism has a construction substantially equivalent to thesecond control mechanism.
 5. The two-axis trajectory control system,according to claim 1, operably associated with one of an airborne and awaterborne vehicle.
 6. A two-axis trajectory control system, comprising:a first control mechanism having outputs coupled with a first pair ofcontrol surfaces, the first control mechanism operable to articulate thefirst pair of control surfaces in unison; and a second control mechanismhaving outputs coupled with a second pair of control surfaces, thesecond control mechanism operable to articulate the second pair ofcontrol surfaces in unison; wherein the first control mechanismcomprises: a motor; an axle coupled with the first pair of controlsurfaces; and a worm shaft operably associated with the motor and theaxle, such that the axle rotates when the motor is activated; andwherein the outputs of the first control mechanism are substantiallycoplanar with the outputs of the second control mechanism.
 7. Thetwo-axis trajectory control system, according to claim 6, wherein thefirst control mechanism further comprises: a motor gear fixedly attachedto the motor; a worm drive gear fixedly attached to the worm shaft andengaged with the motor gear, such that the worm shaft rotates when themotor is actuated.
 8. The two-axis trajectory control system, accordingto claim 6: wherein the axle includes a clevis; and wherein the firstcontrol mechanism further comprises: an axle drive nut engaged with theworm shaft and rotatably attached to the clevis of the axle.
 9. Thetwo-axis trajectory control system, according to claim 8, wherein theaxle drive nut rotates with respect to the axle about a first axis andthe axle rotates about a second axis, which is substantially parallel tothe first axis, when the motor is actuated.
 10. The two-axis trajectorycontrol system, according to claim 6, further comprising: a housinghaving a first portion in which the first control mechanism is disposedand a second portion in which the second control mechanism is disposed;wherein the first control mechanism is disposed in the first portion ofthe housing and the worm shaft is supported by both the first portionand the second portion of the housing.
 11. The two-axis trajectorycontrol system, according to claim 10, wherein the second controlmechanism is disposed in the second portion of the housing and issupported by both the first portion and the second portion of thehousing.
 12. The two-axis trajectory control system, according to claim6, wherein the second control mechanism includes an axle and the axle ofthe first control mechanism includes a bend configured to receive theaxle of the second control mechanism.
 13. The two-axis trajectorycontrol system, according to claim 12, wherein the axle of the secondcontrol mechanism includes a bend, such that the axle of the firstcontrol mechanism is nested with respect to the axle of the secondcontrol mechanism at the bends of the axles.
 14. A two-axis trajectorycontrol system, comprising: a first control assembly operably associatedwith a first pair of control surfaces for articulating the first pair ofcontrol surfaces in unison; and a second control assembly operablyassociated with a second pair of control surfaces for articulating thesecond pair of control surfaces in unison, the second control assemblycomprising: a housing portion; an end cap attached to the housingportion; a motor rotatably supported by the housing portion and the endcap, the motor having an output shaft; a motor gear fixedly attached tothe output shaft of the motor; a worm drive gear engaged with the motorgear; a worm shaft rotatably supported by the housing portion andengaged with the worm drive gear; a worm shaft end stop fixedly attachedto the worm shaft and rotatably supported by the first control assembly;an axle drive nut engaged with the worm shaft; and an axle coupled withthe axle drive nut and the second pair of control surfaces.
 15. Thetwo-axis trajectory control system, according to claim 14, wherein thefirst control assembly comprises: a housing portion, such that the wormshaft end stop is rotatably supported by the housing portion of thefirst control assembly.
 16. The two-axis trajectory control system,according to claim 14, wherein the construction of the first controlassembly corresponds to the construction of the second control assembly.17. The two-axis trajectory control system, according to claim 16,wherein a worm shaft end stop of the first control assembly is rotatablysupported by the second control assembly.
 18. The two-axis trajectorycontrol system, according to claim 14, wherein the first controlassembly comprises: an axle operably associated with the first pair ofcontrol surfaces; wherein the axle of the second control assemblyincludes a bend for receiving the axle of the first control assembly.19. The two-axis trajectory control system, according to claim 18,wherein the axle of the first control assembly includes a bend forreceiving the axle of the second control assembly.
 20. The two-axistrajectory control system, according to claim 14, wherein the axle drivenut rotates with respect to the axle about an axis that is substantiallyparallel with an axis of rotation of the axle when the motor isactivated.
 21. The two-axis trajectory control system, according toclaim 14, further comprising means for retaining the first controlassembly to the second control assembly.